Sarcopenia is a disease associated with ageing caused by a loss of skeletal muscle mass, function and strength. It interferes with the ability to perform everyday activities.
Sarcopenia usually refers to the loss of skeletal muscle mass and strength due to natural ageing, although it could be associated with multiple conditions that could occur in younger populations (i.e., malnutrition, sedentarism, obesity, arthritis, etc.) . These changes may eventually affect a person’s balance and gait and may increase their risk of having falls and other associated problems.
Over time sarcopenia interferes with a person’s capacity to perform essential everyday activities and impacts on their quality of life.
Symptoms & causes
One of the major features of sarcopenia is muscle loss. Everyone loses muscle mass with increasing age, starting from around age 40.
The rate of muscle loss varies from person to person. Generally, we lose around three to eight percent of our muscle mass every decade. When we reach our 60s and 70s we tend to lose muscle mass more rapidly than at any other age.
Sarcopenia is most often seen in inactive people of an older age. However, it can also occur in people who remain physically active throughout their lives. This evidence suggests that factors in addition to a sedentary lifestyle contribute to the development of sarcopenia.
A number of symptoms have been associated with sarcopenia. The extent of muscle loss determines an individual’s number and severity of symptoms.
Symptoms of sarcopenia may include:
- decreased muscle size
- muscle weakness
- loss of endurance
- poor balance
- trouble climbing stairs.
It’s important to recall that the loss of muscle associated with sarcopenia can lead to overall weakness. This in turn may increase the risk of having a fall and therefore increase the risk of fractures and fall-related problems.
Over time, sarcopenia tends to limit a person’s independence because it reduces the activities of living that they can undertake and impacts on their quality of life.
Causes & Risk Factors
A number of causes and risk factors have been identified for sarcopenia. Some of the risk factors are modifiable, meaning we can change them; others are not modifiable, meaning we cannot change them (e.g. our age).
Factors contributing to the development of sarcopenia include:
- advancing age (being 40 years and older)
- having a sedentary or inactive lifestyle
- having a poor diet (increases your risk for malnutrition)
People may have one or more combinations of the above risk factors.
Nutrition and diet are important modifiable risk factors in older people, who often eat less and are at risk of malnutrition. For example, studies have shown that many older people eat less than the recommended amounts of protein, which can lead to malnutrition, as well as negatively affecting muscle mass.
The prevention of sarcopenia centres upon current Australian nutrition and exercise recommendations, including:
- Ensuring an adequate protein intake
- undertaking regular physical activity (exercise).
For some people the use of nutritional supplements may also be appropriate. See the ‘Treatment’ section below, for more information about nutrition, exercise and supplements.
Sarcopenia is usually diagnosed on the basis of the symptoms that a person reports at the time of taking a medical history, and on the results of several investigations.
The results of a test called Dual-energy X-ray Absorptiometry (DXA) in combination with a walking speed test (gait speed) are most often used to help diagnose sarcopenia.
DXA uses low-energy X-rays to measure skeletal mass. DXA is also used to measure bone density to test for the presence of osteoporosis. The use of DXA in combination with grip strength and walking speed tests, can help diagnose sarcopenia. Sometimes additional tests are undertaken such as the short physical performance battery (SPPB).
There are presently no approved medications for the treatment of sarcopenia. However, researchers are investigating the use of certain hormone therapies (e.g. testosterone, growth hormone) to increase lean muscle mass and/or to help people to maintain muscle mass with advancing age. Our teams at AIMSS lead sarcopenia research in Australia and have led the last two major trials testing the effect of new drugs for sarcopenia (still in early phase of development).
The management of sarcopenia presently is focussed on lifestyle changes. This includes increasing exercise, improving nutrition and the use of supplements, as discussed below.
In terms of maintaining muscle, there is a saying you may have heard: “use it or lose it”.
Regular physical activity helps maintain muscle mass and strength, whereas lack of activity leads to muscle shrinkage. Strength training or resistance training improves muscle size, strength, and tone, as well as strengthening the bones, ligaments and tendons.
Strength training can involve the use of weights, resistance bands, exercise machines or a person’s own body weight.
Physical activity and exercise guidelines for all Australians recommend regular physical activity. Adults should participate in muscle-strengthening activities a minimum of 2 days a week.
Older adults should always talk to their GP before starting a new exercise program, to ensure that it is safe for them to exercise.
Consuming a nutritious diet, including adequate amounts of protein, may help to prevent or delay the onset of sarcopenia. People tend to eat less with increasing age and oftentimes are undernourished. A healthy, balanced diet is also important for exercise to be effective and for building muscle.
It has been reported that older adults may need more protein per kilogram, than younger people, to maintain muscle mass.
People diagnosed with sarcopenia need to ensure that they consume appropriate amounts of protein. Meat (e.g. beef, lamb, chicken) and seafood (e.g. trout, salmon), tofu, lentils, beans and quinoa are good sources of protein. When selecting protein rich foods, it’s also important to choose proteins that have low amounts of salt, fat and cholesterol. Referral to a dietician may need to be considered.
Several dietary supplements (e.g. vitamin D) have been shown to improve existing sarcopenia or to help prevent the onset of sarcopenia for those at risk of developing the condition.
For your safety, you should always talk to your doctor before taking any supplements. This will ensure that the supplements you plan to take are safe and effective, and that they will not interact with any of your other medications.